| 摘要 |
<P>PROBLEM TO BE SOLVED: To realize a structure capable of adequately performing a collection of toner attached to a transfer roller regardless of transfer bias variations in a constitution forming patches in line in the width direction of a toner image transferred to a recording material. <P>SOLUTION: An absolute value of transfer bias is larger for heavy paper than for plain paper. Accordingly, a current flown to patches provided in line with a transferred toner image is also larger for the heavy paper. Since toner is negatively charged, when the transfer bias is large, the charge amount is decreased more by electric charge injection. Therefore, a cleaning current is to be smaller for the heavy paper which has the larger absolute value of the transfer bias than for the plain paper. Thereby, the current is prevented from flowing excessively with respect to the charge amount of the patch toner, and the toner collection is adequately performed. <P>COPYRIGHT: (C)2013,JPO&INPIT |
